In an accommodation hole of a dielectric, an external connection terminal, a board connection terminal, and a first coil spring that make up an internal conductor are disposed compactly in a straight line along the hole axis of the accommodation hole. Therefore, an external connection connector can be reduced in size in the radial direction, the projected area on a second board can also be reduced, and it is possible to contribute to the reduction in size of the entire imaging device by the reduction in size of the second board.